The invention relates to a fuel injection valve for internal combustion engines.
One such valve member is disclosed by German Patent Application DE 197 33 905, which was not published by the filing date of the present application. Such a fuel injection valve for internal combustion engines has a valve member which emerges on the outside from the valve body and on which at least two rows of injection ports, located axially one above the other, are provided. The injection parts can be opened in succession in the outward-oriented opening stroke of the valve member. The injection parts have a two-stage hydraulic stroke stop that limits the opening stroke angle of the valve member and is embodied as a hydraulic damping chamber with a relief line that can be opened. The relief line is effected via at least two ground faces on the valve member which can be opened one after the other during the opening stroke motion of the valve member. One of the ground faces can be made to communicate with a low-pressure chamber via a relief conduit that contains a valve. The damping chamber is provided in a shim fastened between the valve body and a valve retaining body and is defined on an axial end opposite the end face of the valve body by a piston, secured to the valve member. The piston is guided by its outer circumference sealingly and slidingly displaceably along the wall of the damping chamber.
The piston is embodied as a plastic, U-shaped sealing ring open toward the damping chamber and pressed onto the shaft of the valve member. A spring is placed in the U-shaped sealing ring. A problem here is that the sealing ring suffers very great wear. Embodying the sealing ring as a metal is problematic because of its vulnerability in terms of tolerances.